When it comes to Nitinol, it has to introduce a new term - shape memory alloy. Shape memory alloy refers to a special alloy that can automatically restore its plastic deformation to its original shape at a certain temperature. Nitinol is the alloy of this type. Nitinol alloy has an expansion ratio of more than 20%, fatigue life of 1*10 to the 7th power, damping characteristics 10 times higher than ordinary springs, and its corrosion resistance is better than the current best medical stainless steel, so it can meet each Engineering applications and medical applications are very good functional material. Let's take a closer look at its performance!
Nickel-titanium alloy, as its name implies, is a binary alloy composed of nickel and titanium.
They have two different crystal phase phases, namely the austenite phase and the martensite phase, due to changes in temperature and mechanical stress. The phase change sequence of the nickel-titanium alloy during cooling is the parent phase (austenite phase)-R phase martensite phase. The R phase is a rhombohedral shape. When the austenite is at a higher temperature (greater than the same temperature: the temperature at which the austenite starts to be heated), or when the load is removed (external force is removed), it will be in the form of a cube, and the texture is hard and shaped. It is also relatively stable. The martensite phase is a state in which the temperature is relatively low (less than Mf: the temperature at which martensite ends) or when loaded (activated by an external force), it appears hexagonal and is malleable and reproducible, but Relatively insufficient is that it is less stable and more deformable.